Here are some resources to help you build your app!

Blog on App tips
http://www.creativebloq.com/app-design/how-build-app-tutorials-12121473
Developer for Android
http://developer.android.com/training/basics/firstapp/index.html
http://developer.android.com/guide/components/index.html
Developer for iTunes
https://developer.apple.com/technologies/ios/